long story short - 10.11.4 is completely unstable on my rMBP. My system keeps freezing and lagging. I've had three kernel panics in one day. I had a backup of 10.11.3 and normally I would just roll back to that but the 10.11.4 also corrupted my Time Machine backup so I cant use it anymore. I happen to have a copy of the GM on a thumb drive and I'm wondering is it possible to install the GM and then install a combo update (10.11.3) over the El Capitan GM?